Astronomy Archives

January 10, 2020January 10, 2020 by Evan Gough

The Perfect Stars to Search for Life On Their Planets

This infographic compares the characteristics of three classes of stars in our galaxy: Sunlike stars are classified as G stars; stars less massive and cooler than our Sun are K dwarfs; and even fainter and cooler stars are the reddish M dwarfs. The graphic compares the stars in terms of several important variables. The habitable zones, potentially capable of hosting life-bearing planets, are wider for hotter stars. The longevity for red dwarf M stars can exceed 100 billion years. K dwarf ages can range from 15 to 45 billion years. And, our Sun only lasts for 10 billion years. The relative amount of harmful radiation (to life as we know it) that stars emit can be 80 to 500 times more intense for M dwarfs relative to our Sun, but only 5 to 25 times more intense for the orange K dwarfs. Red dwarfs make up the bulk of the Milky Way's population, about 73%. Sunlike stars are merely 6% of the population, and K dwarfs are at 13%. When these four variables are balanced, the most suitable stars for potentially hosting advanced life forms are K dwarfs. Credits: NASA, ESA and Z. Levy (STScI)

We tend to think of our Earthly circumstances as normal. A watery, temperate world orbiting a stable yellow star. A place where life has persisted for nearly 4 billion years. It’s almost inevitable that when we think of other places where life could thrive, we use our own experience as a benchmark.

But should we?

January 9, 2020January 9, 2020 by Evan Gough

TESS Finds a Planet That Orbits Two Stars

TOI 1338 b is a circumbinary planet orbiting its two stars. It was discovered by TESS. Image Credit: NASA's Goddard Space Flight Center/Chris Smith

Researchers working with data from NASA’s TESS (Transiting Exoplanet Survey Satellite) have a found a planet that orbits two stars. Initially, the system was identified by citizen scientists as a pair of eclipsing binary stars without a planet. But an intern taking a closer look at that data found that it was misidentified.

January 9, 2020January 9, 2020 by Matt Williams

An Upcoming Impact With the Magellanic Clouds is Already Causing Star Formation in the Milky Way

A newfound cluster of young stars (blue star) sits on the periphery of the Milky Way. These stars probably formed from material originating from neighboring dwarf galaxies called the Magellanic Clouds. Credit: NASA/D. Nidever

For some time, astronomers have known that collisions or mergers between galaxies are an integral part of cosmic evolution. In addition to causing galaxies to grow, these mergers also trigger new rounds of star formation as fresh gas and dust are injected into the galaxy. In the future, astronomers estimate that the Milky Way Galaxy will merge with the Andromeda Galaxy, as well as the Small and Large Magellanic Clouds in the meantime.

According to new results obtained by researchers at the Flatiron Institute’s Center for Computational Astrophysics (CCA) in New York city, the results of our eventual merger with the Magellanic Clouds is already being felt. According to results presented at the 235th meeting of the American Astronomical Society this week, stars forming in the outskirts of our galaxy could be the result of these dwarf galaxies merging with our own.

January 8, 2020January 8, 2020 by Evan Gough

TESS Finds its First Earth-Sized World in the Habitable Zone of a Star

An artist's illustration of TOI 700d, an Earth-size exoplanet that TESS found in its star's habitable zone. New research questions if life really needs planets at all. Image Credit: NASA

NASA’s TESS (Transiting Exoplanet Survey Satellite) has found its first Earth-sized planet located in the habitable zone of its host star. The find was confirmed with the Spitzer Space Telescope. This planet is one of only a few Earth-sized worlds ever found in a habitable zone.

January 8, 2020January 8, 2020 by Evan Gough

Forget Betelgeuse, the Star V Sagittae Should Go Nova Within this Century

An artist's image of a white dwarf drawing material away from its companion. Image Credit: NASA

The star V Sagittae is the next candidate to explode in stellar pyrotechnics, and a team of astronomers set the year for that cataclysmic explosion at 2083, or thereabouts. V Sagittae is in the constellation Sagitta (latin for arrow,) a dim and barely discernible constellation in the northern sky. V Sagittae is about 1100 light years from Earth.

January 8, 2020April 7, 2020 by Matt Williams

This Simulation Shows what We’ll be Able to See with WFIRST

Credits: NASA's Goddard Space Flight Center

When it takes to space in 2025, the Wide-Field Infrared Survey Telescope (WFIRST) will be the most powerful observatory ever deployed, succeeding the venerable Hubble and Spitzer space telescopes. Relying on a unique combination of high resolution with a wide field of view, WFIRST will be able to capture the equivalent of 100 Hubble-quality images with a single shot and survey the night sky with 1,000 times the speed.

In preparation for this momentous event, astronomers at NASA’s Goddard Space Flight Center have been running simulations to demonstrate what the WFIRST will be able to see so they can plan their observations. To give viewers a preview of what this would look like, NASA’s Goddard Space Flight Center has shared a video that simulates the WFIRST conducting a survey of the neighboring Andromeda Galaxy (M31).

January 8, 2020January 8, 2020 by David Dickinson

Our Guide to this Friday’s Penumbral Lunar Eclipse

Penumbral Eclipse — A subtle penumbral lunar eclipse from 2016. Image credit and copyright: Dave Walker.

Ready for the very first lunar eclipse of the year? The first eclipse season of 2020 comes to an end Friday, with a penumbral lunar eclipse. This season overlaps with 2019, when it kicked off with the Boxing Day annular solar eclipse of December 26^th, 2019.

January 7, 2020January 7, 2020 by Evan Gough

M87’s Black Hole is Firing Out Jets that Travel 99% the Speed of Light

Using NASA’s Chandra X-ray Observatory, astronomers have seen that the famous giant black hole in Messier 87 is propelling particles at speeds greater than 99% of the speed of light. Image Credit: NASA/CXC/SAO/B. Snios et al.

Can black holes be famous? If they can, then the one at the heart of the M87 galaxy qualifies. And this famous black hole is emitting jets of material that travel at near the speed of light.

January 7, 2020January 7, 2020 by Matt Williams

Astronomers See the Farthest Galaxy Group Ever Found, When the Universe was Only 5% of its Current Age

Inset: This illustration of the EGS77 galaxy group shows the galaxies surrounded by overlapping bubbles of ionized hydrogen. By transforming light-quenching hydrogen atoms to ionized gas, ultraviolet starlight is thought to have formed such bubbles throughout the early universe, gradually transitioning it from opaque to completely transparent. Background: This composite of archival Hubble Space Telescope visible and near-infrared images includes the three galaxies of EGS77 (green circles). Credits: NASA/ESA/V. Tilvi (ASU)

By looking deeper into space (and farther back in time), astronomers and cosmologists continue to push the boundaries of what is known about the Universe. Thanks to improvements in instrumentation and observation techniques, we are now at the point where astronomers are able to observe some of the earliest galaxies in the Universe – which in turn is providing vital clues about how our Universe evolved.

Using data obtained by the Kitt Peak National Observatory, a team of astronomers with the Cosmic Deep And Wide Narrowband (Cosmic DAWN) Survey were able to observe the farthest galaxy group to date. Known as EGS77, this galaxy existed when the Universe was just 680 million years old (less than 5% of the age of the Universe). Analysis of this galaxy is already revealing things about the period that followed shortly after the Big Bang.

January 7, 2020January 7, 2020 by Evan Gough

Hubble Captured a Photo of This Huge Spiral Galaxy, 2.5 Times Bigger than the Milky Way With 10 Times the Stars

This Hubble Space Telescope photograph showcases the majestic spiral galaxy UGC 2885, located 232 million light-years away in the northern constellation Perseus. The galaxy is 2.5 times wider than our Milky Way and contains 10 times as many stars. A number of foreground stars in our Milky Way can be seen in the image, identified by their diffraction spikes. The brightest star photobombs the galaxy's disk. The galaxy has been nicknamed "Rubin's galaxy," after astronomer Vera Rubin (1928 – 2016), who studied the galaxy's rotation rate in search of dark matter. Credits: NASA, ESA and B. Holwerda (University of Louisville)

This galaxy looks a lot like our own Milky Way galaxy. But while our galaxy is actively forming lots of new stars, this one is birthing stars at only half the rate of the Milky Way. It’s been mostly quiet for billions of years, feeding lightly on the thin gas in intergalactic space.